Botanical Source.—Chondrus crispus, Stackhouse. Irish moss, sometimes called carrageen, has a root-disk, throwing up tufts of many flat, nerveless, slender, cartilaginous fronds, from 2 to 12 inches in height, subcylindrical at the base, but immediately becoming flat, generally dilating from the base upward, until they become 3 or 4 lines wide, then dividing repeatedly and dichotomously, each division spreading and becoming narrower than the preceding one, and taking place at shorter and shorter intervals; the summits are bifid, the segments linear, wedge-shaped, varying greatly in length, rounded or acute, straight or curved, often twisted in such a manner as to give the curled appearance denoted in the specific name. The fructification is roundish or roundish-oval, and subhemispherical. The capsules are imbedded in the disk of the frond, prominent on one side, producing a concavity on the other, containing a mass of minute, roundish, red seeds. The substance is cartilaginous, in some varieties approaching to horny, flexible, and tough. The color is a deep purple-brown, often tinged with a purplish-red, paler at the summit, becoming greenish, and at length white in decay (L).

Gigartina mamillosa, J. Agardh. This plant differs chiefly from the receding in the situation of its cystocarps (sporocarps or capsules), which, instead of being slightly raised and near the extremities of the segments, as in the foregoing species, are borne on short, tuberculated projections or stalks, scattered over the channeled thallus.

History.—These are very common European plants found along the seacoasts, especially along the west shores of Ireland, where quantities of it are gathered. They also grow on the Atlantic shores of this country. Large quantities of Irish moss are annually collected on the Massachusetts coast. It is found attached by its disk to the rocks along the sea, where it is collected in the spring-time, washed, and spread on the sands some distance from the shore-line, and allowed to lie in the sun until it becomes well bleached and of translucent, horny texture, when it is ready for market. It was introduced into medicine in 1831, by Todhunter, of Dublin. Carrageen (more properly carraigeen) signifies, in Irish, "moss of the rock" (Pharmacographia). It is used to some extent in the arts, as sizing for paper and cotton fabrics in calico printing, for filling mattresses, and in this country in making beer. Cattle are sometimes fed on it (Pharmacographia). When fresh its color is somewhat purple, but when cleansed, and dry, as met with in commerce, it is in long crispy pieces, yellowish, or dirty-white, nearly inodorous, and of a mucilaginous taste. It swells up in warm water, and almost entirely dissolves in boiling water, forming a jelly when cold.

Description.—"Yellowish or white, horny, translucent; many-times forked; when softened in water, cartilaginous; shape of the segments varying from wedge-shapedto linear; at the apex emarginate or 2-lobed. It has a slight sea-weed odor, and a mucilaginous, somewhat saline taste. One part of it boiled for 10 minutes with 30 parts of water yields a solution which gelatinizes on cooling, and is not colored blue by iodine T.S."—(U. S. P.).

Chemical Composition.—Irish moss contains oxalate of calcium, compounds of sulphur, iodine, chlorine, bromine, potassium, magnesium, and sodium, and a large portion (as high as 80 per cent), of pectin matter. Flückiger, however, failed to find sulphur in the mucilage. Though starch is not present, Flückiger has shown that if thin pieces of the moss be treated for one day with solution of caustic potash in alcohol, the cell-contents (not cell-walls), react with a dark-blue coloration with the iodide of potassium iodine solution (Pharmacographia). Pereira considered the pectin to be a peculiar modification of mucilage, and has called it carrageenin. Carrageenin may be known from gum by its watery solution not affording a precipitate on the addition of alcohol; from starch by its not assuming a blue color with tincture of iodine; from animal jelly, by tannin causing no precipitate; and from pectin by acetate of lead not throwing down anything, though mucic acid is formed by the action of nitric acid.

Action, Medical Uses, and Dosage.—A decoction of Irish moss, with water or milk, is very nutritious, and may be used as a demulcent in chronic affections of the air passages, chronic diarrhoea and dysentery, scrofula, rickets, enlarged mesenteric glands, irritation of the bladder and kidneys, etc. As a culinary article it may be employed in the preparation of jellies, white soup, blanc mange, etc. The decoction is prepared as follows: Macerate ½ ounce of carrageen in cold or warm water, during 10 minutes; then boil in 3 pints of water, or milk if stronger nourishment is desired, for a quarter of an hour. Strain through linen. Sugar, lemon-juice, tincture of orange-peel, essence of lemon, or other aromatics, as cinnamon or nutmeg, may be employed as flavoring ingredients.

Related Species and Drugs.—Other species of algae are said to be collected with the true Irish moss, the Gigartina acicularis, Lamouroux, having small, cylindrical segments, and having been sold in France as carragheen (Dragendorff). Another species resembling carragheen is the Gigartina pistillata, Lamouroux.

CEYLON MOSS, Fucus amylaceus, Jaffna moss, Edible moss.—The Sphaerococcus lichenoides, Agardh. Irregularly dichotomous, cylindrical, terminating in filiform extremities, of a reddish color (fresh); whitish and brittle when dried. Mucilaginous to the taste, and possessing a faint odor of sea-weed. A delicate moss from 4 to 10 inches in length Contains metarabin, gelose, paramylon, cellulose, gum, other carbohydrates, some soluble in boiling water, others in soda solution, ash, albuminoids, and a substance soluble in alcohol (H. G. Greenish, 1882). This moss is collected from the Indian Ocean (Ceylon coast), and is one of the algae consumed by the Collalia esculenta (Hirundo esculenta), and other species of swallow of the East Indies, and after having been changed in the bird's gizzard, is made to enter into the formation of their nests, which constitute the EDIBLE BIRDS' NESTSof the Chinese. Ceylon moss is used like Irish moss.

AGAR AGAR.—This term is applied to several edible sea-weeds of the East Indies, and some of these varieties, largely employed by the Chinese for sizing silks and preparing jellies, have received commercial names as follows: Chinese (or Japanese) isinglass, or gelatin, derived chiefly from Gelidium corneum, Lamarck;and from Eucheuma spinosum, Agardh; Eucheuma gelatinae, Agardh; Gelidium cartilagineum, Gaillaird; Sphaerococcus compressus, Agardh; Gloiopeltis tenax, J. Agardh, and other algae. This variety occurs in strips about a foot long, or in slender pieces a couple of feet in length, and of a yellow-white color. The strips are employed in bacteriological investigations. It is employed for the same purpose as jellies prepared from animal tissues, and its chief gelatinizing agent is gelose (Payen), a substance having greater gelatinizing properties than carrageenin.

Celebes or Macassar agar agar.—The salt-incrusted Eucheuma spinosum, Agardh, and Eucheuma gelatinae, Agardh, gathered in the straits between the Celebes Isles and Borneo, and occurring as a brown-white moss, with sharp projections on its segments. It contributes to the preparation of Chinese gelatin (see above).

CORSICAN MOSS or HELMINTHOCORTON.—A mixture of a number of sea-algae gathered in the Mediterranean, one species of which, at least, is the Sphaerococcus Helminthocorton, Agardh, (Gigartina Helminthocorton, Greville; Fucus Helminthocorton, Linné). The latter has a cartilaginous, terete, tufted, entangled frond, with setaceous branches, is somewhat dichotomous, and marked indistinctly with transverse streaks. The lower part is dirty-yellow; the branches more or less purple (L.). This is a marine plant, growing on the Mediterranean coast, and especially on the Island of Corsica. The plant is of a cartilaginous consistence, of a dull and reddish-brown color, has a bitter, salt, and nauseous taste, and its odor is rather pleasant. It is found in the form of thick tufts, composed of numerous filaments, united at the base in bundles intermingled together, and fastened to each other by small books, with which the stems are furnished. It is seldom employed in this country. The commercial article consists of some 20 or more species, and may be whitish, yellowish, or of a brownish color. It contains bromides, iodides, and other sails, mucilaginous, and gelatinous material. Water dissolves its active principles. It is anthelmintic. The influence exercised by this substance upon the economy is hardly appreciable—perhaps occasionally a slight irritation of the digestive canal—but it acts very powerfully on the intestinal worms, especially the lumbricoid. Dr. Johnson affirms that when thrown into the rectum, "it destroys any worms domiciliating there as effectually as choke-damps would destroy the life of a miner." The dose is from 10 to 60 grains, mixed with molasses, jelly, or syrup, or in infusion.

DULSE.—The Halymenia palmatus, Agardh, and Halymenia edulis, Agardh, of the Atlantic and Mediterranean Shores. Iodine, bromine and mannit were found in these algae, which appear in Commerce as deep-purple mosses, but when growing they have a rich red hue.

GELOSINE.—A substance under this name was proposed as a basis for preparations for topical use (Brit. Med. Jour., Vol. II, 1886). It is a dried, mucilaginous preparation, occurring in sheets or leaves nearly white in color, and is the product of a Japanese sea-weed. It dissolves in both water and alcohol, but gradually contracting, expels the water or any foreign substance it may contain.